Left picture: The enlargement of the left breast is caused by an endocrinologically active testicular tumor of the right side. This observation emphasizes the necessity of a careful general examination in cases with a seemingly obvious pathology, e.g. a well-known gynecomastia of a male teenager.
Right picture: In this case the diagnosis is a simple unilateral gynecomastia.

Both male teenagers have a medium-sized enlargement of the left breast. There is no difference at all concerning the local findings.
Left picture: The general examination of this boy yields an enlarged right scrotum and developing external genitals.
Right picture: There are minimal signs of a beginning development on general examination.